1. Field of the Invention
The present invention relates to method for fabricating storage electrode of semiconductor device, and in particular to an improved method for fabricating storage electrode semiconductor device wherein a barrier layer is formed by thermally treating a hard mask polysilicon layer for protecting the sacrificial oxide film and the hard mask polysilicon film from damages.
2. Description of the Background Art
FIG. 1 is a cross-sectional view illustrating a method for fabricating a storage electrode of semiconductor device.
Referring to FIG. 1, a sacrificial oxide film 20, a hard mask polysilicon film 30 are sequentially deposited on a semiconductor substrate 10 including a storage node contact plug (not shown). Thereafter, the hard mask polysilicon film 30 and the sacrificial oxide film 20 are etched to form a storage electrode region. A storage electrode (not shown) is then formed in the storage electrode region. The thickness of the sacrificial oxide film 20 should be more than 15000 Å. As the thickness of the sacrificial oxide film 20 is increased, a time period required for etching the sacrificial oxide film 20 is also increased, whereby the thickness of the hard mask polysilicon film 30 must also be increased. However, the hard mask polysilicon film 30 cannot be formed to have more than a predetermined thickness due to limitation in process margin. Therefore, the hard mask polysilicon film 30 is damaged due to over-etching during the etching process of the sacrificial oxide film 20, which causes a bridge between adjacent storage electrodes.